Conventionally, JP2007-263172A discloses a device that calculates an amount of heat generated by a clutch at the time of engagement transition when the clutch is transferred from a disengaged state to an engaged state based on a relative rotation speed difference between an input shaft of the clutch and an output shaft of the clutch and the transmission torque of the clutch. The transmission torque is calculated from the duty value of a solenoid valve for supplying and discharging a hydraulic pressure to the clutch, that is, a hydraulic pressure indicated to the clutch.